JP5942067B2 - Method and apparatus for detecting and managing fermentation state of fermentation medium by ultrasonic irradiation - Google Patents

Description

The present invention relates to a method and apparatus for detecting and managing the fermentation state of a fermentation medium using ultrasonic irradiation, and more specifically, using the ultrasonic propagation time in the fermentation medium in a fermenter. detects the fermentation state of the medium, the detection of the fermentation state of the fermentation medium by ultrasonic irradiation by controlling the ultrasonic level of irradiating the fermentation medium makes it possible to manage the fermentation conditions of the fermentation medium and on the basis thereof The present invention relates to a management method and its apparatus. The present invention utilizes ultrasonic irradiation capable of detecting a fermentation state of the fermentation medium without being limited to the type of the fermentation medium and managing the state of fermentation to stably produce a fermented food . The present invention provides new technologies and new products related to a method and apparatus for detecting and managing the fermentation state of a fermentation medium .

  In the technical field of food production, strong variables such as temperature and pressure are mainly studied as external factors for controlling the growth and metabolism of edible microorganisms. However, the growth and metabolism of food microorganisms are difficult to control because there are few types of operating factors, and attention must always be given to the stable growth of edible microorganisms and the functional expression by metabolism in the food production process.

  For example, taking the case of brewing as an example, the key issues essential to the stable production and quality improvement of brewed products are how well the koji molds and yeasts involved in the koji making and preparation processes grow, work and control. Therefore, there is a strong demand for the examination of new external factors and the development of fermentation control technology using them. In recent years, there has been an increasing interest in research and development of reaction control using physical factors such as pressure, energization treatment, and sound waves, and development and research have been attempted around the world.

  In general, in the fermentation process, the boundary layer between the microbial cells and the medium surrounding the microbial cells is considered to be a barrier to mass transfer inside and outside the microbial cells and to increase the probability that antagonistic inhibition by the fermentation product occurs. On the other hand, the influence of ultrasonic waves on the medium is assumed to be heat, vibration effect, pressure fluctuation, etc. Especially, the bacterial body or medium vibrates due to the ultrasonic vibration effect, and the bacterial body and the medium surrounding it. Minimization of the boundary layer is expected. In addition, it is considered that pressure fluctuation caused by ultrasonic waves may give stress to the bacterial cells and lead to the growth and metabolism of the bacterial cells.

  Various edible microorganisms such as koji molds, yeasts, and lactic acid bacteria are involved in fermented foods such as traditional fermented foods and their production processes. The growth and metabolism of edible microorganisms has a significant effect on the quality of fermented foods. Whether to control is a very important issue. And the challenges in the fermentation process include improving fermentation stability and production efficiency, establishing production management and adjustment systems, efficient capital investment, and adapting to the scale of production, simple, low cost, and versatile. Development of new fermentation technology and equipment with

  In general, ultrasonic waves are sounds that cannot be heard by humans at 20 kHz or higher. As the effect of the ultrasonic waves, heat, pressure fluctuation, vibration effect, and the like can be considered as the influence of the ultrasonic waves on the medium. Due to the vibration effect of ultrasonic waves, for example, the possibility that the bacterial cells or medium in the fermenter vibrate and promote the diffusion of the fermentation medium is assumed. Since various receptors such as stimulating receptors are thought to localize on the cell membrane of the bacterial cells, pressure fluctuations due to low-level ultrasonic irradiation may cause intracellular organelles and functional proteins via some receptors or directly. May affect the growth of cells and the promotion of metabolism.

  Conventionally, regarding the application of ultrasonic irradiation technology to fermentation, prior art documents include, for example, when producing amino acids, peptides, vitamins and nucleic acid-related substances from carbohydrate raw materials, such as sugar raw materials such as white rice liquor. The amount of glutathione produced in the fermented koji can be greatly increased by irradiating ultrasonically the koji fermented with yeast added to the koji or its pressed and filtered residue. It is described that physiologically active substances such as peptides, vitamins and nucleic acid-related substances can be produced (Patent Document 1).

  In addition, in other prior art documents, in the method for producing a lactic acid fermentation broth using rice bran or brown rice flour as a raw material, the bad breath and bad taste of rice bran and brown rice are obtained by applying ultrasonic waves to the obtained fermentation broth. It is described that a significantly reduced lactic acid fermentation broth can be obtained (Patent Document 2).

  In addition, in other prior art documents, purified water and minerals are added to and mixed with the ceramide composition as a raw material, and then mixed with this ceramide composition mixture, koji mold, yeast, citric acid bacteria, When fermented with koji molds containing lactic acid bacteria and acetic acid bacteria and mixed with an organic acid in the ceramide composition fermented liquid and kept at a temperature of 35 ° C. to 45 ° C., it is super It is described that stirring and flowing while applying sonic vibration, aging and organic acid fermentation (Patent Document 3).

  In addition, other prior art documents reduce the dissolved oxygen by releasing bubbles by vibration energy such as ultrasonic waves, anaerobic respiration, that is, activate organisms that use inorganic compounds other than oxygen as electron acceptors, fermentation It is described that a living organism having an organic compound as an electron acceptor is activated to improve the growth rate of, for example, lactic acid bacteria and yeast (Patent Document 4).

  In another prior art document, an ionized mineral liquid is added to purified water to generate fine bubbles having a diameter of 50 μm or less, and further, ultrasonic waves of 25 to 30 kHz are irradiated to physically stimulate the fine bubbles. To give ultrafine air bubbles water, add water to the mixed raw material containing starch, cereals, seeds and eggshell, which is the ionized mineral liquid, and heat the starch to 50-100 ° C to gelatinize the starch, 30-30 It is described that the temperature is kept at 40 ° C., and koji molds are added and subjected to complex fermentation, thereby dramatically improving functions and effects such as an active action on living organisms (Patent Document 5).

  Further, other prior art documents describe that the aging time of rice wine can be considerably shortened by ultrasonic waves with a frequency of 20 KHz, and the effect varies depending on the sake raw material (Non-Patent Document 1).

  In other prior art documents, it has been described that the time required to reach the maximum dry mycelium weight was shortened by ultrasonic irradiation in the fermentation of Ecomthecium ashbyii to produce riboflavin (vitamin B2) ( Non-patent document 2).

In addition, in other prior art documents, it is described that fermentation time can be reduced to 50 to 64% of the conventional fermentation by weak ultrasonic irradiation of 30 mW / cm ^{2 in} fermentation of wine, beer, sake, etc. Patent Document 3).

  In addition, as a prior art, there is known a method for growing edible microorganisms by ultrasonic waves that irradiates ultrasonic waves to increase the growth of bacterial bodies of food microorganisms and the generation of metabolites. However, when this method is applied to an industrially practical volume of fermentation medium, it is necessary to develop a method of ultrasonic irradiation suitable for a large volume of fermentation medium.

  Furthermore, as a prior art, there is known a method of monitoring the fermentation process of yogurt by ultrasonic wave, which grasps the degree of coagulation by fermentation from the speed of sound of ultrasonic wave. In this method, the speed of sound is obtained from the phase difference between the signal measured with water and the signal measured with yogurt. If the temperature of water or yogurt changes, measurement will not be possible.

Japanese Unexamined Patent Publication No. 7-16096 JP-A-8-280341 JP 2009-100725 A JP 2009-190018 A JP 2009-226386 A Japanese Patent Application No. 2011-010287

Chang et al. (2002). The application of 20 kHz ultrasonic waves to accelerate the different of wines. Food Chemistry, 79, 501-506 Dai et al. (2003). Low ultrasonic stimulates fermentation of riboflavin producing strain Ecesthecium ashbyii. Colloids and Surfaces B: Biointerfaces, 30, 37-41 Matsuura et al. (1994). Acceleration of cell growth and ester formation by ultrasonic wave irradiation. Journal of Fermentation and Bioengineering, 77 (1), 36-40 Food and Technology, Technical Explanation, “Yogurt Fermentation Process Monitoring by Ultrasound” (2008-10)

As described above, several examples of development of fermentation technology using ultrasonic waves have been reported as prior art, but these technologies irradiate ultrasonic waves on small-volume to large-volume fermentation media. It has not yet been sufficient as a practically usable technique for producing a fermented food stably and stably. Therefore, in this technical field, the ultrasonic fermentation is uniformly and efficiently applied to industrially practical fermentation media to detect the fermentation status of the fermentation media and manage the fermentation status of the fermented food. Therefore, there has been a strong demand to establish a method and apparatus for detecting and managing the fermentation state of a practical fermentation medium using a new ultrasonic wave capable of stably producing a fermented food.

The present invention was developed in such a situation, and 1) an apparatus capable of uniformly irradiating ultrasonic waves to a small-volume to large-capacity fermentation medium in a fermenter, and 2) a fermenter. The method of detecting the fermentation state of the fermentation medium using the ultrasonic propagation time in the fermentation medium, and controlling the intensity of the ultrasonic wave irradiating the fermentation medium and ON / OFF of irradiation / non-irradiation based on 2) above An object of the present invention is to provide a method and apparatus for detecting and managing a fermentation state of a fermentation medium using new ultrasonic waves capable of stably producing a fermented food by controlling the fermentation state of the fermentation medium. Is.

The present invention for solving the above-described problems comprises the following technical means.
(1) A way you detect the fermentation conditions of the fermentation medium, the ultrasonic waves irradiated from the ultrasonic element to the fermentation medium of the fermentation tank in the ultrasonic irradiation unit installed in the fermentation tank is, ultra The ultrasonic wave propagation time, which is the time required for reflecting the reflected wave by the ultrasonic element reflected by the inner wall of the fermenter that reflects the sound wave or the reflector disposed in the fermenter, is received by the ultrasonic element. Measured by obtaining the peak position of the autocorrelation function of the received signal at, and based on the ultrasonic propagation time or based on the value obtained by adding the correction due to the temperature of the fermentation medium to the ultrasonic propagation time. how you and detecting the fermentation state.
(2) The peak of the autocorrelation function of the ultrasonic reflected wave signal, further interpolated by interpolating the peak position, to measure the ultrasonic wave propagation time, method towards according to (1).
(3) By measuring the temperature of the fermentation medium with a temperature sensor installed in the vicinity of the ultrasonic element and using the temperature data from the temperature sensor to correct the ultrasonic propagation time, it is affected by temperature fluctuations. performing no measurement, methods who according to (1) or (2).
(4) The fermentation state of the fermentation medium is detected by the method according to any one of (1) to (3), and based on the result, switching between irradiation / non-irradiation of ultrasonic irradiation and / or irradiation of ultrasonic waves by controlling the intensity, how to manage the fermentation conditions of the fermentation medium.
(5) Irradiate the fermentation medium with ultrasonic waves, measure the ultrasonic propagation time, detect the fermentation state, and then select either ultrasonic irradiation or non-irradiation according to the detection result of the fermentation state , then measuring the ultrasonic wave propagation time, continuing the cycle, to control the fermentation rate of the fermentation medium, method towards according to any one of (1) to (4).
(6) A fermenter, an ultrasonic element unit rotatably installed in the fermenter, and an ultrasonic irradiation unit having a connection unit structure in which a plurality of the ultrasonic element units are connected to form a rotation axis, An apparatus that uniformly irradiates the fermentation medium in the fermenter with ultrasonic waves by ultrasonic rotation irradiation by an ultrasonic irradiation unit.
(7) The apparatus according to (6), including a reflector and / or a liquid level detection sensor fixed to the ultrasonic irradiation unit.
(8) In a connecting unit structure in which a plurality of ultrasonic element units are connected to form a rotation axis, the surfaces of the ultrasonic elements of each ultrasonic element unit are connected in series in an arbitrary direction, The apparatus as described in (6).

Next, the present invention will be described in more detail.
The present invention is to provide a way you detect the fermentation conditions of the fermentation medium, a way you detect the fermentation conditions of the fermentation medium, ultra in ultrasonic irradiation unit installed in the fermentation tank The ultrasonic wave applied to the fermentation medium in the fermenter from the acoustic wave element is reflected by the inner wall of the fermenter that reflects the ultrasonic wave or the reflector disposed in the fermenter, and the reflected wave signal is reflected by the ultrasonic wave. The ultrasonic propagation time, which is the time required for reception by the ultrasonic element, is measured by obtaining the peak position of the autocorrelation function of the received signal in the ultrasonic element, and based on the ultrasonic propagation time, or the ultrasonic wave It is characterized in that the fermentation state of the fermentation medium is detected based on a value obtained by correcting the propagation time by the influence of the temperature of the fermentation medium.

Further, the present invention is to provide a equipment capable ultrasonic irradiation, as a basic configuration, the fermenter is being installed rotatably to the normal equipment, the fermentation tank be disposed fermenter And an ultrasonic irradiation unit having a connecting unit structure in which a plurality of ultrasonic element units are connected to form a rotational axis, and optionally a liquid level detection sensor, ultrasonic element overheat prevention means (thermal Protector), ultrasonic noise prevention means, etc., and ultrasonic irradiation by the ultrasonic element unit to irradiate the fermentation medium in the fermenter uniformly with ultrasonic waves. .

  In the method of the present invention, the peak of the autocorrelation function of the reflected wave signal of the ultrasonic wave is obtained and further interpolated by interpolating the peak position to measure the ultrasonic propagation time, or the ultrasonic element Measuring the temperature of the fermentation medium with a temperature sensor installed in the vicinity, and using the temperature data from the temperature sensor to correct the ultrasonic propagation time, thereby performing measurement that is not affected by temperature fluctuations. This is a preferred embodiment.

  In the method of the present invention, the fermentation state of the fermentation medium is detected by the above method, and based on the result, switching between irradiation / non-irradiation of ultrasonic irradiation and / or controlling the irradiation intensity of ultrasonic waves, Manage the fermentation state of the fermentation medium, or irradiate the fermentation medium with ultrasonic waves, measure the ultrasonic propagation time, detect the fermentation state, and then, depending on the detection result of the fermentation state, It is a preferred embodiment to select either irradiation or non-irradiation, then measure the ultrasonic propagation time, and continue the above cycle to control the fermentation rate of the fermentation medium.

  Furthermore, the apparatus of the present invention includes a reflector and / or a liquid level detection sensor fixed to the ultrasonic irradiation unit, and a connection unit structure in which a plurality of ultrasonic element units are connected to form a rotation axis. It is a preferred embodiment that the surface of the ultrasonic element of the ultrasonic element unit is positioned in an arbitrary direction and connected by series connection, and optionally includes an ultrasonic element heating preventing means.

Next, the structure of the ultrasonic irradiation unit used in the present invention will be described in detail.
In the present invention, the ultrasonic irradiation unit constituting the ultrasonic irradiation unit has a unit structure in which the ultrasonic element unit can be connected. The ultrasonic element unit can be arbitrarily connected in series according to the size of the fermenter, and the interval between the units, that is, the interval between the ultrasonic elements is a spacer, for example, the white resin of FIG. An arbitrary interval can be set by changing the length of the portion.

  In the present invention, for example, the ultrasonic wave irradiation unit can be appropriately provided with a liquid level detection sensor having an arbitrary shape and structure. When the liquid level detection sensor detects the fermentation medium, for example. Only an ultrasonic irradiation structure can be used. As a result, it is possible to prevent damage to the ultrasonic element and wasteful power consumption.

  The above-described ultrasonic irradiation units connected in series can be arranged so as to rotate as a rotation axis. Moreover, the angle between the units when the ultrasonic irradiation units are connected in series can be arbitrarily set. The attachment angle of the ultrasonic element itself is also arbitrary, and can be set, for example, at a predetermined angle that is not necessarily perpendicular or perpendicular to the rotation axis. It becomes possible to irradiate sound waves.

  The ultrasonic element in the rotating ultrasonic irradiation unit can be provided with a rotating brush (not shown) at the top of the unit so that electric power can be supplied through the rotating brush. The number of rotating brushes is arbitrary, and an ultrasonic signal, a temperature signal, etc., which will be described later, can also be acquired through the rotating brush.

Next, detection of the fermentation state of the fermentation medium using ultrasonic waves will be described in detail.
In the present invention, the time required for the ultrasonic wave to propagate through the fermentation medium is obtained, whereby the fermentation state of the fermentation medium, that is, the change in elastic modulus and density associated with the fermentation can be detected. Specifically, in the fermentation medium in the fermenter, the ultrasonic wave irradiated from the ultrasonic element in the ultrasonic irradiation unit is disposed on an object that reflects the ultrasonic wave, that is, the inner wall of the fermenter or any position. The time required for reflection by a reflector such as a reflector and reception of the reflected wave by the ultrasonic element (ultrasonic propagation time) is obtained, and the peak position of the autocorrelation function of the received signal in the ultrasonic element is obtained. By measuring by this, the fermentation state can be detected. Since the ultrasonic velocity is obtained by dividing the reciprocating distance between the ultrasonic element and the reflector by the ultrasonic propagation time, measuring the ultrasonic propagation time measures the ultrasonic velocity. Is equivalent to that.

  In the present invention, the above time measurement is performed by obtaining a peak of the autocorrelation function of the reflected wave signal of the ultrasonic wave, and further interpolating the peak value by interpolation, thereby accurately measuring a minute time change. It is possible to grasp accurately.

  A temperature sensor can be appropriately installed in the vicinity of the ultrasonic element to measure the temperature of the fermentation medium. In general, the ultrasonic propagation time in the fermentation medium varies depending on the temperature of the fermentation medium. By using the temperature data of the temperature sensor to correct the ultrasonic propagation time, the influence of the variation in the temperature of the fermentation medium can be reduced. Measurement that is not received becomes possible. Moreover, the detection of the fermentation state of the fermentation medium, that is, the measurement of the ultrasonic propagation time can be performed using one or more units among a plurality of ultrasonic irradiation units. In this case, it is possible to arbitrarily attach a reflector such as a reflector to the ultrasonic irradiation unit.

Control of ultrasonic irradiation based on the detection result of the fermentation state of the fermentation medium using ultrasonic waves will be described.
In the present invention, the fermentation state of the fermentation medium is detected, that is, the ultrasonic propagation time is measured, and on the basis of the result, ON / OFF of irradiation / non-irradiation of ultrasonic irradiation is switched, or the irradiation intensity of ultrasonic waves is changed. Can be controlled.

  When detecting ultrasonic waves, one or more of a plurality of ultrasonic irradiation units, for example, for 10 minutes, 1 minute is irradiated with ultrasonic waves to measure ultrasonic propagation time, and fermentation medium is fermented. Detect state. Then, for the subsequent 9 minutes, either ultrasonic irradiation or non-irradiation is automatically selected according to the detection result of the fermentation state of the fermentation medium. For example, if the fermentation is delayed, ultrasonic irradiation is selected. After that, if the ultrasonic propagation time is measured again for 1 minute and the above cycle is continued, it is possible to irradiate the ultrasonic wave so that the speed at which the fermentation proceeds is optimal or optimal.

  The basic principle of the ultrasonic wave propagation time (that is, the speed of sound of ultrasonic waves) in the present invention will be described with reference to FIG. First, using an apparatus that generates a pulsed electric signal, for example, a pulsar receiver, the ultrasonic element is vibrated, and the fermentation medium in the fermenter is irradiated with ultrasonic waves. The irradiated ultrasonic waves are reflected by a reflector, for example, a wall surface of a fermenter, an optional reflector, and an ultrasonic element, and reciprocate between the ultrasonic element and the reflector. At this time, the reciprocating ultrasonic wave is received by an ultrasonic element, and the received wave is amplified by an amplifier, for example, a pulsar receiver. By analyzing the time difference between the peaks of the received ultrasonic wave signal thus obtained with an oscilloscope or the like, the ultrasonic propagation time in the fermenter, that is, the speed of sound of the ultrasonic wave can be measured.

  Next, a method for analyzing the ultrasonic propagation time using the self-function will be described with reference to FIG. In analyzing the ultrasonic propagation time, the autocorrelation function of the ultrasonic wave reception signal is calculated, and the ultrasonic propagation time is calculated from the peak position of the autocorrelation function, that is, the value on the horizontal axis. In FIG. 2, the peak position can be detected by enlarging the position of 30.00 μm. In this case, the peak position of the autocorrelation function can be obtained accurately and easily from the time difference between the peaks of the ultrasonic wave reception signal, and if the peak position of the autocorrelation function is interpolated by interpolation, the temporal position is high. The ultrasonic propagation time can be obtained. In FIG. 2, the vicinity of the peak position of the autocorrelation function is approximated by a second-order polynomial to interpolate the peak position, but may be approximated and interpolated by a third-order polynomial or the like.

Next, the relationship between ultrasonic propagation time and fermentation will be described in detail with reference to FIG.
Looking at the relationship between the ultrasonic propagation time and fermentation, as shown in FIG. 3, the pH, which is the index of fermentation, is similar to the change in ultrasonic propagation time or sound velocity, and the fermentation proceeds. Accordingly, it can be seen that the ultrasonic wave propagation time decreases (the sound speed increases). This indicates that the progress of fermentation can be detected from the ultrasonic propagation time or the speed of sound.

  Next, when the influence of the temperature change with respect to the ultrasonic propagation time is seen, as shown in FIG. 4, it can be seen that the ultrasonic propagation time varies greatly with the temperature change of the fermentation medium. This suggests that the fermentation state cannot be accurately determined from the ultrasonic wave propagation time as it is, that is, correction of the influence of temperature is necessary.

  Next, referring to FIG. 5, a method for correcting the influence of temperature will be described with reference to FIG. Looking at the relationship between the ultrasonic propagation time and temperature, as shown in FIG. 6, there is a relationship that the ultrasonic propagation time increases (slows the speed of sound) when the temperature decreases, but it is completely on the straight line. It turns out that it does not fit. This is because the temperature waveform and the ultrasonic wave propagation time waveform are misaligned because the position of the temperature sensor and the ultrasonic wave irradiation position do not exactly match.

In order to correct the influence of temperature, the relationship between the ultrasonic wave propagation time and temperature is shifted to the right by 0 to 4 minutes in order to see the difference between the approximate line and the data, as shown in FIG. It can be seen that, when shifted by 2 minutes, the average of the absolute value of the difference from the approximate straight line data becomes the smallest and fits the straight line most. Here, in the case of a 2-minute shift, when the temperature changes by 1 ° C., the ultrasonic propagation time changes by −3.53 × 10 ⁻⁸ (s), that is, as shown in FIG. It can be seen that −3.53 × 10 ⁻⁸ .

Therefore, the correction value is calculated by the following formula.
Formula: Correction value = Ultrasonic propagation time−3.53 × 10 ⁻⁸ × (correction temperature−temperature before 2 minutes)
The correction coefficient is determined by the positional relationship between the ultrasonic element and the temperature sensor, the type of fermentation medium, and the shape and capacity of the fermenter. If these do not change, the correction coefficient may be obtained in advance. Even when the correction coefficient cannot be obtained in advance, such as when the type of fermentation medium is not determined, the relationship with the temperature as shown in FIG. 8 may be obtained during the fermentation, and the correction coefficient may be obtained as needed. Moreover, although the above equation is a linear equation, a quadratic equation or a cubic equation may be used.

  Regarding temperature correction, for example, as shown in FIG. 9, the relationship between temperature and ultrasonic propagation time is similar to the corrected graph and pH measurement value. It can be seen that the influence of temperature can be eliminated from the time, whereby the fermentation state of the fermentation medium, that is, the progress of fermentation, etc. can be detected from the ultrasonic wave propagation time after temperature correction.

  For example, as shown in FIG. 10, the method 1 reflects ultrasonic waves at the inner wall of the fermenter and measures the ultrasonic propagation time between the inner wall of the fermenter and the ultrasonic element. It is a method to do. This method is simple, but the measurement accuracy is deteriorated when the rotation axis is shaken, and if the distance to the wall surface is long, reflection of ultrasonic waves may not be received. Method 2 is a method in which a reflector such as a reflector is fixed to the ultrasonic element unit, the ultrasonic wave is reflected on the reflector, and the ultrasonic propagation time between the reflector and the ultrasonic element is measured. In this method, it is necessary to rotate the reflector together with the ultrasonic unit, but there is an advantage that the reflected wave of the ultrasonic wave can be received stably.

In the present invention, any of the method 1 and the method 2 can be used as a method for receiving the reflected ultrasonic wave. By this invention, an ultrasonic wave can be irradiated to the wide range of the fermentation medium in a fermenter, and, thereby, the effect of ultrasonic irradiation can be exerted extensively. The fermentation state of the fermentation medium can be detected without using a pH meter, and unlike the pH meter, the elastic modulus (hardness) and density of the fermentation medium can be directly evaluated. No cleaning or calibration of measured values is required. Further, by rotating the ultrasonic element, it is possible to accurately know the distribution of the fermentation state in the fermenter, for example, the presence or absence of a bias in the fermentation state. Moreover, measurement using water is unnecessary, and even if there is a change in temperature, accurate measurement can be performed, and fermentation can proceed at a suitable speed while detecting the fermentation state. The present invention is not limited to the type of fermentation medium, and is a new technology relating to a method and apparatus for detecting and managing the fermentation state of a fermentation medium by ultrasonic irradiation for detecting and managing the fermentation state of the fermentation medium. It is useful for providing new products.

The present invention has the following effects.
(1) Ultrasonic waves can be applied to a large-capacity fermentation medium, and the effects (promotion of growth and metabolism of edible microorganisms) of the prior art (Patent Document 6 etc.) can be applied to a large-capacity fermentation medium Can be obtained.
(2) The present invention can be applied to fermenters having various capacities. For example, the configuration of the apparatus can be easily changed according to the size of the fermenter.
(3) The proportion of the fermentation medium in the fermenter is arbitrary, for example, it may be in a full tank state or may be less than half, or the amount of fermentation medium may change during the fermentation process. The ultrasonic element can be prevented from being damaged by controlling ON / OFF of the ultrasonic element according to the amount of the fermentation medium.
(4) Ultrasonic waves can be irradiated to a wide range of the fermentation medium in the fermenter, and thereby the effects of ultrasonic irradiation can be exerted widely.
(5) The state of fermentation of the fermented food can be detected using ultrasonic waves, whereby the fermentation state can be managed.
(6) The fermentation state of the fermentation medium can be detected without using a pH meter or the like, and unlike the pH meter, the elastic modulus (hardness) and density of the fermentation medium can be directly evaluated.
(7) As in the measurement with a pH meter, it is not necessary to clean the apparatus or calibrate the measurement value for each measurement, and by rotating the ultrasonic element, the distribution of the fermentation state in the fermenter, for example, It is possible to know the presence or absence of fermentation state bias.
(8) Unlike the prior art, measurement using water is not necessary, and accurate measurement is possible even if there is a change in temperature.
(9) While detecting the fermentation state of the fermentation medium, based on the result, the ultrasonic irradiation is switched on and off, and the intensity of the ultrasonic wave is controlled to proceed the fermentation at a suitable or optimal speed. Can do.

It is description which shows the analysis method (basic principle) of ultrasonic propagation time (sound velocity). It is explanatory drawing which shows the analysis method (method using an autocorrelation) of ultrasonic propagation time. It is explanatory drawing which shows the relationship between ultrasonic propagation time and fermentation. It is explanatory drawing which shows the influence at the time of temperature fluctuation. It is explanatory drawing which shows the correction method (connection diagram) of the influence of temperature. It is explanatory drawing which shows the correction method (relationship between ultrasonic propagation time and temperature) of the influence of temperature. It is explanatory drawing which shows the correction method (relationship between ultrasonic propagation time and temperature) of the influence of temperature. It is explanatory drawing which shows the correction method (relationship between ultrasonic propagation time and temperature) of the influence of temperature. It is explanatory drawing which shows the example of temperature correction. It is explanatory drawing which shows the reception method of an ultrasonic reflected wave. The photograph of the pilot plant fermentation system of an Example is shown. The ultrasonic element unit of an Example and a photograph are shown. The example of the axis | shaft formed by connecting the ultrasonic element of an Example 5 is shown. The example which equipped the fermenter tank with the ultrasonic element rotating shaft of an Example is shown.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by the following Examples.

  In this embodiment, an example of developing a pilot plant fermentation system is shown. This system is equipped with a fermenter tank (capacity: 100 liters), ultrasonic elements (5 built-in), ultrasonic rotation irradiation means, ultrasonic element overheat prevention thermal protector, liquid level detection function, and measures against ultrasonic noise. As a result, an oscillation circuit was built in the rotating shaft. The outline is shown in FIG.

  The ultrasonic element unit used in this example is shown in FIG. That is, this unit has an ultrasonic element (oscillation frequency: 2.4 MHz) and a liquid level detection sensor, and when the liquid level sensor enters the liquid level, ultrasonic output is started. FIG. 13 shows an example in which five ultrasonic element units are connected to form a shaft.

  In this embodiment, five ultrasonic elements (interval: 100 mm) are connected to form a shaft. However, the number of ultrasonic elements connected can be arbitrarily connected in series, and the ultrasonic elements can be matched to the size of the fermenter. Unit axes can be created. In the figure, the element spacing can be arbitrarily set by changing the length of the white resin portion. FIG. 14 shows an example in which a fermenter tank is attached to the ultrasonic element rotation shaft.

The present invention was applied to soymilk, which is an example of a fermentation medium, and inoculated with lactic acid bacteria, which is an example of edible microorganisms, and the fermentation state of soymilk inoculated with lactic acid bacteria was detected.
In this example, the fermentation state was detected under conditions where the temperature of the fermentation medium did not vary.
Lactic acid bacteria ( Lactobacillus plantarum LB-K-2 strain) obtained by stationary culture in 10 mL of MRS medium at 30 ° C. for 15 hours, diluted with lactic acid bacteria culture solution (about 10 ⁹ cells / mL) with physiological saline, Soy milk (Organic soy milk manufactured by Tokyo Meiraku Co., Ltd.) was inoculated so as to be about 10 ⁴ cells / g.

  This was put in a plastic container and allowed to stand in a thermostat and fermented. The temperature in the fermenter was 30 ° C. An ultrasonic element is installed in the container, and ultrasonic waves are irradiated into the fermentation medium as needed, and the ultrasonic wave reflected from the ultrasonic element and the stainless steel reflector installed at a distance of about 3.5 cm is applied to the ultrasonic element. And the ultrasonic wave propagation time, that is, the time required for the ultrasonic wave to reciprocate between the ultrasonic element and the reflecting plate was obtained. The ultrasonic wave propagation time was obtained at a frequency of 8 times per minute, and this was time averaged every minute.

  At this time, by connecting a pulser receiver (Olympus Model 5800) to the ultrasonic element, a pulsed voltage is applied to the ultrasonic element to irradiate the ultrasonic wave from the ultrasonic element, and the received ultrasonic signal Amplification was performed. A pulsar receiver and an oscilloscope were connected, and the amplified ultrasonic wave was observed with an oscilloscope.

  Furthermore, the oscilloscope was connected to a personal computer, the observed waveform on the oscilloscope was transferred to the personal computer, and the autocorrelation function of the observed waveform was calculated by software operating on the personal computer. Next, the peak position of the autocorrelation function was obtained by software operating on a personal computer, and further interpolated by interpolation to increase the resolution of the peak position, and then the ultrasonic propagation time was obtained. For comparison, the pH value was also measured at regular intervals using a pH meter.

  FIG. 3 shows the relationship between the ultrasonic wave propagation time and the pH value thus obtained. In general, it is possible to know the progress of fermentation from the pH value, and in this example as well, it can be seen that the pH value decreases with time and the fermentation proceeds. On the other hand, the ultrasonic propagation time also decreased with the passage of time (sound speed increased), and a correlation with the pH value was also observed. Thus, it was confirmed from the relationship between the ultrasonic propagation time and the pH value in FIG. 3 that the progress of fermentation can be detected from the ultrasonic propagation time.

In the present Example, it implemented on the conditions from which the temperature of a fermentation medium fluctuates.
In the same manner as in Example 2 performed under conditions where the temperature of the fermentation medium did not change, lactic acid bacteria were inoculated into the soy milk and left in a thermostatic bath. However, the temperature of the thermostatic bath was varied at regular intervals so that the temperature of the fermentation medium varied about 1 ° C. around about 26.5 ° C. The distance between the ultrasonic element and the reflecting plate was about 2.5 cm.

  Moreover, similarly to the case of Example 1 performed under the condition that the temperature of the fermentation medium does not fluctuate, the ultrasonic propagation time was obtained by software on a personal computer using a pulsar receiver, an oscilloscope, and an ultrasonic element. Furthermore, a temperature sensor was installed in the vicinity of the ultrasonic element to measure the temperature of the fermentation medium, and the temperature signal was also recorded on a personal computer as needed. For comparison, the pH value was also measured at regular intervals using a pH meter.

FIG. 9 shows the relationship between the ultrasonic propagation time, temperature, and pH value obtained in this way. Further, FIG. 9 also shows the ultrasonic propagation time in which the influence of temperature is corrected by the following equation.
Expression: Temperature correction value of ultrasonic propagation time = ultrasonic propagation time−3.34 × 10 ⁻⁸ × (correction temperature−temperature two minutes before the time when the ultrasonic propagation time is acquired)

  Here, the correction temperature was 28 ° C. That is, the ultrasonic propagation time when the temperature was 28 ° C. was obtained. The temperature correction value of the ultrasonic propagation time decreased with time, and a correlation with the pH value was also observed. Thus, according to this example, it was confirmed that the progress of fermentation can be detected from the temperature correction value of the ultrasonic propagation time.

As described in detail above, the present invention according to the method for detecting and managing the fermentation state of the I Ri fermentation medium to the ultrasonic irradiation and apparatus, the present invention is, for example, depending on fermenter sizes Since the configuration of the apparatus can be easily changed, it can be applied to fermenters of various capacities. Further, the proportion of the fermentation medium in the fermenter is arbitrary, for example, it may be full or less than half, and the amount of the fermentation medium may change during the fermentation process. Accordingly, the ultrasonic element can be prevented from being damaged by controlling ON / OFF of the ultrasonic element. The present invention uses 1) an apparatus capable of uniformly irradiating a small-volume to large-volume fermentation medium with ultrasonic waves in the fermenter, and 2) utilizing the ultrasonic propagation time in the fermentation medium in the fermenter, Based on the method of detecting the fermentation state of the fermentation medium, 2) above, the intensity of the ultrasonic wave irradiating the fermentation medium and ON / OFF are controlled, and the fermentation state of the fermentation medium is managed to stably produce the fermented food. The present invention is useful as a method and apparatus for detecting and managing a fermentation state of a fermentation medium using new ultrasonic waves that can be produced .

Claims (8)

A way you detect the fermentation conditions of the fermentation medium, the ultrasonic waves irradiated in the fermentation medium of the fermenter from the ultrasonic element in the ultrasonic irradiation unit installed in the fermentation tank is, reflecting the ultrasound The ultrasonic propagation time, which is the time required for the reflected wave to be received by the ultrasonic element after being reflected by the inner wall of the fermenter or the reflector disposed in the fermenter, is the received signal in the ultrasonic element. The fermentation state of the fermentation medium is measured based on the ultrasonic propagation time or based on the value obtained by correcting the ultrasonic propagation time by the influence of the temperature of the fermentation medium. how you and detecting. The peak of the autocorrelation function of the reflected wave signal of the ultrasonic wave, further interpolated by interpolating the peak position, to measure the ultrasonic wave propagation time, methods who claim 1. By measuring the temperature of the fermentation medium with a temperature sensor installed in the vicinity of the ultrasonic element, and correcting the ultrasonic propagation time using the temperature data from the temperature sensor, measurement that is not affected by temperature fluctuations is possible. performing, method person according to claim 1 or 2. By detecting the fermentation state of the fermentation medium by the method according to any one of claims 1 to 3, and based on the result, switching between irradiation / non-irradiation of ultrasonic irradiation and / or controlling the irradiation intensity of ultrasonic waves , how to manage the fermentation state of fermentation media. Irradiate the fermentation medium with ultrasonic waves, measure the ultrasonic propagation time, detect the fermentation state, and then select either ultrasonic irradiation or non-irradiation according to the detection result of the fermentation state, measuring ultrasonic wave propagation time, continuing the cycle, to control the fermentation rate of the fermentation medium, method towards according to any one of claims 1 to 4.   A fermenter, an ultrasonic element unit rotatably installed in the fermenter, an ultrasonic irradiation unit having a connection unit structure in which a plurality of the ultrasonic element units are connected to form a rotation axis, and the ultrasonic irradiation An apparatus that uniformly irradiates the fermentation medium in the fermenter with ultrasonic waves by ultrasonic rotation irradiation by the unit.   The apparatus of Claim 6 which has a reflecting plate fixed to the ultrasonic irradiation unit, and / or a liquid level detection sensor.   7. The connecting unit structure in which a plurality of ultrasonic element units are connected to form a rotation axis, and the surfaces of the ultrasonic elements of each ultrasonic element unit are positioned in arbitrary directions and connected in series. The device described.